Selling toasted patties on the burger

McDonald's Centurion, Hendrik Verwoerd Drive On Friday evening, 4th February 2022, I bought a burger meal via the Drive Thru. When getting home and busy eating, I got a bad taste in my mouth and looking at the burger, the patty on the burger was burn, it was toasted, I wont even give this to a dog. When returning the burger to McDonald's, the manager Tepelo was not helpful, he first search for something to scratch the cheese from the patty to look if it is really burn, when a anyone can see from the side that the patty has been burn. Although Tepelo replace the burger, he made me feel very uncomfortable as If I did something wrong. I told him replacing the burger was not the issue, does McDonald's dont have any standards that they will serve their customers toasted patties on the burger. I have never been serve such burn food and still have to pay for it. This is a total disgrace.